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# Easy vector question (C4) Watch

1. The vector has a magnitude of 3

Find the two possible values of k.

I know the answer is +/- 4, but how do you get it? I tried using pythagoras, but I can't seem to get the correct answer.

Any help would be appreciated
2. (Original post by jaydemikaela)
The vector has a magnitude of 3

Find the two possible values of k.

I know the answer is +/- 4, but how do you get it? I tried using pythagoras, but I can't seem to get the correct answer.

Any help would be appreciated
I tried Pythagoras and it worked out fine?
5^2+k^2+2^2=(3sqrt5)^2
k^2=45-29=16
3. The magnitude of the vector has a magnitude of .

Try substituting in your numbers and it will come out right.

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